The present invention relates to food patty-forming machines. The invention particularly relates to an improved filling arrangement for a food patty-forming machine.
Food patty-forming, or patty-molding, machines are described for example in U.S. Pat. Nos. 3,952,478; 4,054,967; 4,182,003; and 4,329,828, and PCT published application WO 99/62344, herein incorporated by reference.
In one type of food patty-forming machine a mold plate, having patty-shaped cavities, is reciprocated between a fill position and a knock out position. The cavities are located above or below a food product delivery apparatus. Within the food product delivery apparatus, the food product, such as ground beef or ground poultry, is pumped by a plunger through a manifold and then upwardly or downwardly through a fill slot and eventually into the mold cavities. When the mold plate is in the fill position, food product is delivered under pressure through the fill slot into the cavities, forming patties.
A breather plate is arranged above or below the mold plate. The breather plate includes breather holes that communicate or express air out of the mold cavities while food product is being filled into the cavities from below or above. The breather holes are typically located at a position above the cavities being filled that is distant from the position of the fill slot, so that a uniform patty shape can be achieved as the air within the mold cavities and within the food product is expelled through the breather holes. During filling, the food product delivered through the fill slot advances through a transverse flow area defined by a width and height of the cavity, through the cavity toward the breather holes. After filling of the cavities, the mold plate is then shifted to the knock out position where the mold cavities are extended forward of the breather plate. The patties are then knocked out of the cavities by a knockout mechanism.
The present inventor has recognized that when the formed patties are thin, i.e., formed within cavities of a thin mold plate, such as 0.25 inch thick or thinner mold plates, extreme product pressure is required to fill the cavities. Particularly, the present inventor has recognized that extreme product pressure is required to force cold and stiff food product, particularly ground or whole muscle poultry, through the thin passage provided by the thickness of the thin mold plate. Elevated pressures increase forces on machine components, which in turn increases friction of sliding components. Elevated pressures also contribute to increased occurrence of leaks and spraying.
The present inventor has recognized that it would be advantageous to provide a food patty-forming machine which overcame the above-mentioned drawbacks and produced a food patty having a uniform food density and thickness.
The invention contemplates an improved food patty-forming machine of the type having a reciprocating mold plate having at least one cavity, the mold plate reciprocated between a fill position and a knock-out position, the cavity filled with food product from a fill slot open to one side of the cavity when the cavity is in the fill position. The improvement comprises the use of a fill recess in registry with the cavity in the fill position, the fill recess allowing an increased flow area for food product to advance within the cavity during filling. Preferably, the fill recess is formed into a face of a breather plate, the breather plate also having breather holes for expelling air from within the cavity during filling.
Preferably, the mold plate includes multiple cavities arranged side-by-side in the transverse direction. The fill slot and fill recess can be common to the cavities.
As the mold plate is moved into its fill position, with the fill slot in registry with the cavities, food product held in the fill recess is forced from the fill recess into the cavities. Further food product is forced through the fill recess, and directly through the cavities, into the cavities until the cavities are filled. As food product is filled into the mold cavities, air is expelled through both the breather holes.
The invention is particularly suitable for machines wherein the breather plate and the fill slot are on opposite sides of the mold plate, although not limited to such machines. Such machines typically utilize the mold plate to seal off the fill slot from atmosphere as the mold plate moves back and forth between the fill position and the knock out position. By forming the fill recess into the breather plate, the advantage of using the mold plate to seal off the fill slot is retained.
Numerous other advantages and features of the present invention will become readily apparent from the following detailed description of the invention and the embodiments thereof, from the claims and from the accompanying drawings.